1. Field of the Invention
Embodiments of the present invention relate to an optical film, and more particularly to a liquid crystal display (LCD) device having the optical film.
2. Description of the Related Art
Generally, a liquid crystal display device includes a thin film transistor substrate, a color filter substrate, a liquid crystal display panel having a liquid crystal layer interposed between the thin film transistor substrate and the color filter substrate, and backlight unit having a separate light source for supplying light to the liquid crystal display panel. The liquid crystal display device includes a polarizer formed on at least one of the top and bottom surfaces of the liquid crystal display panel. The backlight unit includes the light source emitting light and optical films directing the light emitted from the light source toward the top surface of the liquid crystal display panel. The optical films include at least one of a diffusion film, a prism film, and a protection film. Although light emitted from the light source is directed to the polarizer through the optical films, only some of the light having a polarization direction parallel to a transmission axis of the polarizer is transmitted through the polarizer.
Light polarized by the polarizer is incident onto the liquid crystal display panel and is modulated according to the molecular arrangement of the liquid crystal layer of the liquid crystal display panel. Thus, an image can be displayed on a screen of the liquid crystal display device. Other components of the light that are blocked by the polarizer are reflected from the polarizer or absorbed by the polarizer. Therefore, a large portion of light emitted from the light source dose not reach the liquid crystal display panel. As a result, the overall brightness of the backlight is not used, and more power is required for the backlight unit to provide sufficient brightness to the liquid crystal display device.